lib: time: export usec_to_tick()

In the UEFI Stall() boottime service we need access to usec_to_tick().

Export the function.

Remove redundant implementation in arch/arm/mach-rockchip/rk_timer.c.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

arch/arm/mach-rockchip/rk_timer.c

@@ -20,13 +20,6 @@ static uint64_t rockchip_get_ticks(void)
 	return timebase_h << 32 | timebase_l;
 }
 
-static uint64_t usec_to_tick(unsigned int usec)
-{
-	uint64_t tick = usec;
-	tick *= CONFIG_SYS_TIMER_RATE / (1000 * 1000);
-	return tick;
-}
-
 void rockchip_udelay(unsigned int usec)
 {
 	uint64_t tmp;

include/time.h

@@ -4,6 +4,7 @@
 #define _TIME_H
 
 #include <linux/typecheck.h>
+#include <linux/types.h>
 
 unsigned long get_timer(unsigned long base);
 
@@ -21,6 +22,14 @@ unsigned long timer_get_us(void);
  */
 void timer_test_add_offset(unsigned long offset);
 
+/**
+ * usec_to_tick() - convert microseconds to clock ticks
+ *
+ * @usec:	duration in microseconds
+ * Return:	duration in clock ticks
+ */
+uint64_t usec_to_tick(unsigned long usec);
+
 /*
  *	These inlines deal with timer wrapping correctly. You are
  *	strongly encouraged to use them

lib/time.c

@@ -139,7 +139,7 @@ unsigned long __weak notrace timer_get_us(void)
 	return tick_to_time(get_ticks() * 1000);
 }
 
-static uint64_t usec_to_tick(unsigned long usec)
+uint64_t usec_to_tick(unsigned long usec)
 {
 	uint64_t tick = usec;
 	tick *= get_tbclk();